WO2009032263A1 - Antenne à dipôle replié à grande échelle pour applications rfid en champ proche - Google Patents

Antenne à dipôle replié à grande échelle pour applications rfid en champ proche Download PDF

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Publication number
WO2009032263A1
WO2009032263A1 PCT/US2008/010348 US2008010348W WO2009032263A1 WO 2009032263 A1 WO2009032263 A1 WO 2009032263A1 US 2008010348 W US2008010348 W US 2008010348W WO 2009032263 A1 WO2009032263 A1 WO 2009032263A1
Authority
WO
WIPO (PCT)
Prior art keywords
another
dipole antenna
electrically conductive
antenna
conductive elements
Prior art date
Application number
PCT/US2008/010348
Other languages
English (en)
Inventor
Bing Jiang
Richard Campero
Steve Trivelpiece
Original Assignee
Vue Technology, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Vue Technology, Inc. filed Critical Vue Technology, Inc.
Priority to EP08829851A priority Critical patent/EP2186163B1/fr
Priority to CA2696936A priority patent/CA2696936C/fr
Priority to ES08829851T priority patent/ES2397123T3/es
Publication of WO2009032263A1 publication Critical patent/WO2009032263A1/fr
Priority to HK10110821.2A priority patent/HK1145270A1/xx

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
    • H01Q1/2208—Supports; Mounting means by structural association with other equipment or articles associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems
    • H01Q1/2216—Supports; Mounting means by structural association with other equipment or articles associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems used in interrogator/reader equipment
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/0008—General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
    • G06K7/10316—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves using at least one antenna particularly designed for interrogating the wireless record carriers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q11/00—Electrically-long antennas having dimensions more than twice the shortest operating wavelength and consisting of conductive active radiating elements
    • H01Q11/12—Resonant antennas
    • H01Q11/14—Resonant antennas with parts bent, folded, shaped or screened or with phasing impedances, to obtain desired phase relation of radiation from selected sections of the antenna or to obtain desired polarisation effect
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q25/00—Antennas or antenna systems providing at least two radiating patterns
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q7/00—Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/16—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole
    • H01Q9/26—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength
    • H01Q9/265—Open ring dipoles; Circular dipoles

Definitions

  • the present inventions relate to a large scale folded dipole antenna or array of such antennas, used in a RPID system that requires large coverage, low cost, low thickness (profile), such as smart shelves or other storage or display fixtures used in UHF or microwave RFID item-level applications.
  • Radio frequency identification (RFID) systems typically use one or more reader antennas to send electromagnetic carrier waves encoded with digital signals to items containing or equipped with RFID tags.
  • RFID tags to identify an item or person is well known in the art.
  • passive RFID systems an RFID tag is powered by the electromagnetic carrier wave. Once powered, the passive tag interprets the radio frequency (RF) signals and provides an appropriate response by creating a timed, intermittent disturbance in the electromagnetic carrier wave. These disturbances, which encode the tag response, are sensed by the reader through one of the reader's antennas, thus completing the reader-tag communications loop.
  • the tag contains its own power source. In the active RFID systems, the power is used for communications with the reader by creating tag's own carrier wave and encoded RF signals; while in the semi-passive RFID systems, tag's power supply is solely used for powering the tag's IC, not for communication.
  • Item-level RFID can empower users to precisely track inventory and location of tagged items in real time or near real time.
  • large quantities of tagged items are placed in a crowded environment, and often the passive RFID tags on or in those items have very small form factors.
  • the reader antennas In order to realize item-level visibility, the reader antennas have to be brought into close proximity with these passive RFID tags due to the tags' short working range.
  • traditional antennas are designed for far-field applications, not for near-field applications.
  • the present inventions relate to a large scale folded dipole antenna or array of such antennas.
  • an antenna assembly for use with a predetermined carrier signal having a predetermined frequency and wavelength associated therewith, comprising: a dipole antenna, the dipole antenna including two electrically conductive elements of unequal lengths that are also not simple multiples of each other so that when transmitting at the wavelength of the carrier signal, at least one moving null is created within the dipole antenna, wherein each of the two electrically conductive elements is connected at one end to a common feed-point and has another end, wherein the two electrically conductive elements form a loop-like shape with a small gap between the another end of each of the two electrically conductive elements.
  • a method of eliminating reception dead- spaces for a plurality of stationery RFID tagged items using a stationery RFID reader dipole antenna associated therewith that transmits at a predetermined carrier signal having a predetermined frequency and wavelength associated therewith to each of the plurality of stationery RFID tagged items comprising the steps of: providing the stationery RFID reader dipole antenna with two electrically conductive elements of unequal lengths that are also not simple multiples of each other so that when transmitting at the wavelength of the carrier signal, at least one moving null is created within the stationery RFID reader dipole antenna, wherein each of the two electrically conductive elements is connected at one end to a common feed-point and has another end, wherein the two electrically conductive elements form a loop-like shape with a small gap between the another end of each of the two electrically conductive elements; and causing the stationery RFID reader dipole antenna to transmit the carrier signal to the plurality of stationery RFID tagged items so that the carrier signal within the stationery RFID reader dipole antenna will
  • FIG. 1 shows a large scale folded dipole antenna with an impedance matching network, as described in the embodiments of the current inventions.
  • FIG. 2 shows examples of alternative antenna shapes.
  • a large scale folded dipole antenna intended for near-field RFID implementations has been invented and is described below.
  • the antenna's overall length (in at least one dimension) is preferably at least twice the wavelength of the RFID carrier (baseband) wave.
  • a "large” dipole antenna is long relative to the wavelength of the waves being sent and received by the antenna.
  • the traditional dipole antenna described in the prior art has only two conducting arms, usually with equal but sometimes with different lengths, though not with features that cause moving nulls as described herein. Dipole antennas have the attractive features of low cost, low profile, easy fabrication, and simple installation.
  • large dipole antennas usually have nulls in their radiation patterns (points along the antenna where the emitted field strength is weak and where the antenna's ability to sense incoming signals is also weak), and the number of nulls increases with the increase of dipole size. The exact location of these nulls along the length of the traditional dipole antenna depends upon the wavelength of the signal and the length of the dipole.
  • the current invention describes an antenna in which the outer ends of two conducting arms of unequal lengths are brought close to one another, forming a two-dimensional antenna (similar to a loop with a gap).
  • the current invention deals with a bent or "folded” dipole antenna in which the conducting arms have been “folded” around so that the conducting arms of the antenna are curved, and fall upon or generally upon a circle, ellipse, oval, square, or other two-dimensional shape. It is emphasized that the outer ends of the two curved or bent conducting arms are not touching each other, but are near each other.
  • the antenna although bent or folded into a curved form, is not a true loop antenna, but is still a true dipole antenna in which the two conducting antenna arms are connected to a common feed cable or feed-point at the source ends, and left free (electrically unconnected) at the outer ends of the conducting arms.
  • This cost-efficient antenna provides a desirable large coverage area without dead zones (or negligibly small dead zones) in its proximity, suitable for item-level RFID implementations.
  • the nulls In the linear dipole antenna of the prior art, the nulls generally result from standing waves. In the newly invented two-dimensional folded or bent dipole antenna in which the two conducting arms have unequal lengths, the symmetry of the prior art antenna is broken, and the impact of the nulls is minimized.
  • the newly invented dipole antenna can be implemented on or inside the horizontal or vertical surfaces of retail, warehouse, home, or other fixtures such as (but not limited to) cabinets, shelves, drawers, racks, cases, desks, counters, chests, bins, or other places of storage used to hold and monitor RFID-tagged items.
  • FIG. 1 is a drawing illustrating an exemplary dipole antenna assembly in accordance with the preferred embodiment.
  • conducting arms or conducting elements 100 and 110 form a loop-like shape with a gap 120 between the outer ends of the conducting arms 100 and 110.
  • conducting arm 100 is longer than conducting arm 110. Because of the length difference, the currents propagating along these two conductors have different phase shift, i.e., the electric field along the coverage is not symmetric or antisymmetric. As a result, the dead zones along the symmetric centers are removed or minimized.
  • the invention requires that the dimension of the antenna along its long arm is preferably larger than or equal to one or two wavelengths, and the shorter arm is also not a simple multiple of the longer arm, which differentiates itself from other dipole antennas in near-field RFID applications.
  • Arms 100 and 110 can be solid metal or other types of electrically conductive materials such as stamped foils or films printed with conductive ink, and are attached or fixed on a supporting dielectric material or substrate (not shown in FIG.l).
  • Matching network 130 is a circuit block easily anticipated by one skilled in the art which converts the antenna impedance to some standard or common reader terminal impedance (usually 50 ohm).
  • the matching network may consist of some appropriate combination of resistors, inductors, or capacitors, according to a large number of alternative circuit designs known to those skilled in the art.
  • a coaxial or "coax" cable is used to connect the antenna and the reader, with one conducting arm of the antenna electrically attached to the core conductor of the coaxial cable, and the other conducting arm attached to the shielding mesh (outer conductive layer) of the coaxial cable. If a balun is used in the system, the twisted two-wire cable can be used to connect the antenna and the reader.
  • the antenna assembly shown in FIG. 1 provides a large coverage area along the antenna cross section without dead zones or noticeable dead zones to RFID tags with regular size, which is realized mainly by tuning the location and size of the gap between the two conducting arm ends.
  • the antenna can be implemented in any pattern or geometrical shape (e.g., square, rectangular, triangle, ellipse, or circle) or be fed from different common-feed point locations.
  • geometrical shape e.g., square, rectangular, triangle, ellipse, or circle
  • FIG. 2 Several of these shape alternatives are shown in FIG. 2, including a rectangular shape 210, rectangular shape fed from the corner 220, triangle shape 230, and ellipse 240.
  • Irregular shapes can also be used (like the shape of the State of Texas) as can regular shapes.
  • reader antennas are provided within storage fixtures or supporting fixtures (for example, shelves, cabinets, drawers, or racks) for transporting RF signals between, for example, an RPID reader and an RFID tag.
  • the reader antennas may be placed in a variety of configurations which include but are not limited to configurations in which, for each antenna, the two conducting arms with unequal lengths are folded to form a loop-like shape with a gap.
  • the size of antenna is larger than one wavelength (corresponding to the specified frequency band) at least along one dimension of the antenna.
  • the RFID-enabled storage fixtures or supporting fixtures are equipped with multiple dipole antennas. Furthermore, in the preferred embodiment, these RFID-enabled fixtures are implemented using an intelligent network in which the antennas are selected, activated, and otherwise managed by a supervisory control system consisting of one or more controllers and a host computer or host network, as described in U.S. Patent No. 7,084,769, and U.S. Patent Application No. 20060232382, both of which are expressly incorporated by reference herein.
  • the RFID-enabled fixtures can receive the carrier signals from different RFID reader antennas at different periods of time, and in a preferred mode of operation where each of the different RFID reader antennas will transmit such that there are at least one, and preferably two, different moving nulls therein.
  • This redundancy features can be used both for further assurance that reception dead-space is eliminated when all of the reader antennas and tagged items are stationery, as well as to include security features achievable by using more than one RFID reader antenna for transmission.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Toxicology (AREA)
  • Artificial Intelligence (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Electromagnetism (AREA)
  • General Health & Medical Sciences (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Details Of Aerials (AREA)

Abstract

L'invention concerne une antenne équipée pour une utilisation avec une porteuse prédéterminée ayant une fréquence prédéterminée et une longueur d'onde lui étant associée, comprenant : une antenne dipôle qui comprend deux éléments électriquement conducteurs (100, 110) de longueurs inégales qui ne sont également pas de simples multiples l'une de l'autre de sorte que lors d'une émission à la longueur d'onde de la porteuse, au moins un zéro mobile est créé à l'intérieur de l'antenne dipôle, chacun des deux éléments électriquement conducteurs (100, 110) étant connecté à une extrémité à un point d'alimentation commun et comportant une autre extrémité, les deux éléments électriquement conducteurs formant une forme de boucle avec un petit espace (120) entre les autres extrémités des deux éléments électriquement conducteurs.
PCT/US2008/010348 2007-08-31 2008-09-02 Antenne à dipôle replié à grande échelle pour applications rfid en champ proche WO2009032263A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP08829851A EP2186163B1 (fr) 2007-08-31 2008-09-02 Antenne à dipôle replié à grande échelle pour applications rfid en champ proche
CA2696936A CA2696936C (fr) 2007-08-31 2008-09-02 Antenne a dipole replie a grande echelle pour applications rfid en champ proche
ES08829851T ES2397123T3 (es) 2007-08-31 2008-09-02 Antena dipolar de gran escala plegada para aplicaciones RFID de campo próximo
HK10110821.2A HK1145270A1 (en) 2007-08-31 2010-11-19 A large scale folded dipole antenna for near-field rfid applications

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US96957607P 2007-08-31 2007-08-31
US60/969,576 2007-08-31

Publications (1)

Publication Number Publication Date
WO2009032263A1 true WO2009032263A1 (fr) 2009-03-12

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ID=39985951

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2008/010348 WO2009032263A1 (fr) 2007-08-31 2008-09-02 Antenne à dipôle replié à grande échelle pour applications rfid en champ proche

Country Status (6)

Country Link
US (1) US8730121B2 (fr)
EP (1) EP2186163B1 (fr)
CA (1) CA2696936C (fr)
ES (1) ES2397123T3 (fr)
HK (1) HK1145270A1 (fr)
WO (1) WO2009032263A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2234206A1 (fr) * 2009-03-27 2010-09-29 Brother Kogyo Kabushiki Kaisha Unité d'antenne à boucle
EP2461423A1 (fr) * 2010-12-03 2012-06-06 Metrologic Instruments, Inc. Système de surveillance d'article électronique
TWI478443B (zh) * 2011-04-27 2015-03-21 Hon Hai Prec Ind Co Ltd 多輸入輸出天線
TWI488356B (zh) * 2011-08-05 2015-06-11 Acer Inc 通訊電子裝置及其天線結構
WO2016090638A1 (fr) * 2014-12-12 2016-06-16 Hong Kong R&D Centre for Logistics and Supply Chain Management Enabling Technologies Limited Antenne dipôle pour étiquette d'identification par radiofréquence (rfid)

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US8056819B2 (en) * 2008-10-14 2011-11-15 Hong Kong Applied Science And Technology Research Institute Co., Ltd. Miniature and multi-band RF coil design
US8508367B2 (en) * 2009-09-21 2013-08-13 Checkpoint Systems, Inc. Configurable monitoring device
MX2012003457A (es) * 2009-09-21 2012-08-03 Checkpoint Systems Inc Sistema, método y aparato de rastreo de productos de venta por menudeo.
JP5299518B2 (ja) * 2009-11-04 2013-09-25 株式会社村田製作所 情報処理システム
US20110183624A1 (en) * 2010-01-28 2011-07-28 Thiagarajar College Of Engineering Devices and Methods for Phase Shifting a Radio Frequency (RF) Signal for a Base Station Antenna
GB201006907D0 (en) * 2010-04-26 2010-06-09 Cambridge Entpr Ltd RFID TAG interrogation systems
FI124191B (fi) * 2010-11-23 2014-04-30 Stora Enso Oyj Tunnisteen käsittävä hylsy
US20140002320A1 (en) * 2011-03-16 2014-01-02 Kenichi Asanuma Antenna apparatus operable in dualbands with small size
KR101819220B1 (ko) * 2012-03-14 2018-01-16 삼성전자주식회사 무선통신 시스템에서 안테나 구조 및 동작 방법
US20140345534A1 (en) * 2013-05-27 2014-11-27 Hana Micron America Inc. Livestock Feeder-Embedded RFID Antenna Apparatus
US9691540B2 (en) * 2014-12-19 2017-06-27 Mediatek Inc. Hybrid passive device and hybrid manufacturing method
US11116984B2 (en) * 2017-09-08 2021-09-14 Advanced Bionics Ag Extended length antenna assembly for use within a multi-component system
US10171133B1 (en) 2018-02-20 2019-01-01 Automated Assembly Corporation Transponder arrangement

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GB2254440A (en) 1991-01-31 1992-10-07 Stanley William Waterman Detecting microwave radiation
CA2414124A1 (fr) 2002-12-12 2004-06-12 Research In Motion Limited Antenne a commande de rayonnement en champ proche
US20050093677A1 (en) * 2003-11-04 2005-05-05 Forster Ian J. RFID tag with enhanced readability
US20050119035A1 (en) * 2002-09-26 2005-06-02 Kentaro Miyano Radio terminal device antenna and radio terminal device
US20060208957A1 (en) * 2005-03-18 2006-09-21 Kabushiki Kaisha Toyota Chuo Kenkyusho Dipole antenna having a periodic structure

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US6147653A (en) * 1998-12-07 2000-11-14 Wallace; Raymond C. Balanced dipole antenna for mobile phones
SG76615A1 (en) * 1999-04-16 2000-11-21 Univ Singapore An rf transponder
US7253717B2 (en) * 2000-11-29 2007-08-07 Mobile Technics Llc Method and system for communicating with and tracking RFID transponders
US7084769B2 (en) 2002-01-09 2006-08-01 Vue Technology, Inc. Intelligent station using multiple RF antennae and inventory control system and method incorporating same
JP2005244283A (ja) * 2004-02-24 2005-09-08 Omron Corp アンテナおよびｒｆタグ
US7893878B2 (en) * 2006-12-29 2011-02-22 Broadcom Corporation Integrated circuit antenna structure

Patent Citations (5)

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Publication number Priority date Publication date Assignee Title
GB2254440A (en) 1991-01-31 1992-10-07 Stanley William Waterman Detecting microwave radiation
US20050119035A1 (en) * 2002-09-26 2005-06-02 Kentaro Miyano Radio terminal device antenna and radio terminal device
CA2414124A1 (fr) 2002-12-12 2004-06-12 Research In Motion Limited Antenne a commande de rayonnement en champ proche
US20050093677A1 (en) * 2003-11-04 2005-05-05 Forster Ian J. RFID tag with enhanced readability
US20060208957A1 (en) * 2005-03-18 2006-09-21 Kabushiki Kaisha Toyota Chuo Kenkyusho Dipole antenna having a periodic structure

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2234206A1 (fr) * 2009-03-27 2010-09-29 Brother Kogyo Kabushiki Kaisha Unité d'antenne à boucle
EP2461423A1 (fr) * 2010-12-03 2012-06-06 Metrologic Instruments, Inc. Système de surveillance d'article électronique
TWI478443B (zh) * 2011-04-27 2015-03-21 Hon Hai Prec Ind Co Ltd 多輸入輸出天線
TWI488356B (zh) * 2011-08-05 2015-06-11 Acer Inc 通訊電子裝置及其天線結構
WO2016090638A1 (fr) * 2014-12-12 2016-06-16 Hong Kong R&D Centre for Logistics and Supply Chain Management Enabling Technologies Limited Antenne dipôle pour étiquette d'identification par radiofréquence (rfid)

Also Published As

Publication number Publication date
CA2696936C (fr) 2016-03-29
US20090079573A1 (en) 2009-03-26
HK1145270A1 (en) 2011-04-08
US8730121B2 (en) 2014-05-20
EP2186163A1 (fr) 2010-05-19
EP2186163B1 (fr) 2012-12-12
CA2696936A1 (fr) 2010-02-16
ES2397123T3 (es) 2013-03-04

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